Device to provide an increase in fabrication properties of severely work hardened sheet metal



Sept. 28, 1965 c. E. MAIER 3,208,259 DEVICE TO PROVIDE AN INCREASE IN FABRICATION PROPERTIES OF SEVERELY WORK HARDENED SHEET METAL Filed April 6, 1962 2 Sheets-Sheet 1 I16 J- 61 20 a 5 Q I'Ta, s"

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33 INVENTOR CUIZTlS E. Mmaz fit M ATTORNEYS Sept. 28, 1965 c. E. MAIER 3,208,259

DEVICE To PROVIDE AN INCREASE IN FABRICATION PROPERTIES OF SEVERELY WORK HARDENED SHEET METAL Filed April 6, 1962 2 Sheets-Sheet 2 L0 0) mfnggmm INVENTOR Cola-r15 "E-MAIEK ATTORNEYS United States Patent Office 3,208,259 Patented Sept. 28, 1965 3,208,259 DEVICE TO PROVIDE AN INCREASE IN FABRI- CATION PRDPERTIES F SEVERELY WORK HARDENED SHEET METAL Curtis E. Mater, Chicago, lll., assignor to Continental Can gompany, Inc., New York, N.Y., a corporation of New ork Filed Apr. 6, 1962, Ser. No. 185,676 17 Claims. (Cl. 72-163) This invention relates in general to new and useful improvements in apparatus for use in the manufacture of sheet metal, and more particularly relates to a novel device to accomplish alternate flexing of continuous tin plate strip and like sheet metal in order to produce alternate tensile and compressive plastic strains in the metal along the line transverse to the direction of strip motion to provide an increase in fabrication properties of severely work hardened sheet metal while increasing the ductility of such strip or sheet metal.

In the manufacture of certain types of sheet metal, particularly thin steel strip and sheet, the necessary reduction in thickness is obtained by heavily cold rolling the starting metal stock. The resultant strip has been severely cold worked, frequently by more than 80% reduction, and although very hard and strong, it does not have adequate ductility for many uses. For example, if the ultimate product is to be tin plated steel for the making of cans, the hard rolled steel in conventional practice must be annealed and then temper rolled to a reduction of about only 1%. This very slight reduction imparts flatness and also masks the yield point elongation of such steel which otherwise would be detrimental to can making or other fabricating processes which might be employed, and yet this minor reduction does not noticeably impair the ductility resulting from the prior anneal.

When such conventional tin plate is desired in thinner gauges, i.e., less than .008 inch thick, a variety of difficulties are encountered. For example, when thin rolled strips are pulled through the electrolytic tinning line, the applied tensile force used to pull the strip sometime results in expensive fracture of the strip Within the electroplating line. In order to avoid this difficulty, the steel industry has introduced a new type of tin plate to provide the desired thinner gauges of metal, which new type of plate is produced in such a manner that it is less costly, per unit area, to produce than heretofore.

The new type of tin plate is produced by additional substantial cold rolling reductions after the metal strip stock has been annealed. The initial cold rolling is to a somewhat thicker gauge than normal; followed by annealing, tin plating and a subsequent cold reduction of the order of 30% to 60%, resulting in a finished gauge of as low as 0.0044 inch, and even lower, if desired. Unfortunately, while the finished product has a desired thinness and also a desirable high strength and hardness, these qualities have been obtained by an almost complete sacrifice of ductility and by a marked directionality of properties. Tensile testing of such material indicates a transverse elongation of the order of 1% or less in a 2 inch gauge length and a longitudinal elongation of from less than 1% to 3%.

In producing such hard strong but brittle tin plate, it is possible to electroplate with tin after the second cold reduction to final gauge and do so without fractures from tension while pulling the strip through the electrotinning line. This may be done because the hard rolled plate is so much stronger than conventional plate and can Withstand the tensile forces encountered. An alternative possibility is to electroplate with a thicker coating of tin prior to the second cold reduction so that upon this 30% to 60% cold rolling the tin coating is reduced in thickness to the same degree as the steel substrate. In either case, the properties of the steel are essentially identical for equivalent cold reductions so that the problems of utilizing this material are the same.

When cans, which have been made from either of these new types of tin plate, have the rolling direction parallel to the can axis, severe fracturing of the plate is encountered during manufacture. Fracture occurs primarily during forming of the side seam hook and during fianging of the can body. These can making operations are ones in which large locallized plastic tensile strains are introduced into the metal in a direction transverse to the rolling direction. When these problems are avoided by having the can bodies made with the rolling direction of the tin plate in a circumferential direction, fracture of the cans has been encountered when, during rough handling, dents were produced in the body wall below the end seam seal. Therefore, in order to exploit further this newly introduced type of tin plate for can making, some of the ductility of the metal must be restored. Thermal treatment, such as annealing after the second cold reduction, is not practical since the costs of this operation would make the final product more expensive whereas the major benefit achieved by its use is the desire for cost savings. Furthermore, if the tin coating were put on prior to the second cold reduction, this coating will alloy with the steel at the required steel annealing temperatures and thereupon forming an excessive amount of undesired hard and brittle tin-iron alloy.

The present invention is primarily directed to a machine for operating on this new type of tin plate which has been given a substantial cold reduction before or after tin plating to increase the ductility thereof, or to a presently unavailable but potentially still lower cost plate made without any annealing at all so that it is in the full hard state with or more coldreduction followed by electroplating with tin.

In the past, metal sheets to be formed into can bodies have been subjected to a grain breaking process wherein immediately prior to the shaping of the sheets in a can making process, the sheets are passed through a grain breaker to assure the formation of a perfectly round cylinder by preventing the formation of flutes in the can body cylinder as fabricated at high speeds. This grain breaker consists of several rollers disposed in vertical relation. However, While these rollers have produced the desired grain breaking and curvature of the individual can body blanks, the flexing of the sheets has been relatively light, and there has been no accompanyingincrease in ductility of the sheets so mechanically treated.

In the steel industry, in order to remove ripples from steel sheets, as well as other steel shapes, it is common practice to pass the steel through leveling rollers. As the steel passes through the leveling rollers, it is ultimately flexed with a resultant flattening of the metal. Such roller levelers used today have only a limited number of pairs of alternatingly spaced rollers of approximately 1 /2 to 3 inches in diameter. However, the steel industry does not flex the steel enough to substantially exceed the yield strength except at initially non-flat portions since the objective is to simply flatten or straighten and not to change any of the physical or mechanical properties of the material.

The present invention proposes broadly to use a machine wherein the metal strip is reversely flexed a large number of times, with the number of complete cycles of flexing being in the vicinity of times, thereby requiring on the order of 100 rollers in each set of rollers, there being two sets of rollers disposed in meshing relation, the machine being constructed to have a generally circular path for the strip being worked upon, so that the space required for the machine is reduced to a minimum.

Another object of this invention is to provide a novel machine for reverse flexing a hardened metal strip to increase the ability thereof to withstand fabrication by increasing the ductility of the strip, the machine utilizing a very large number of small diameter rollers, the rollers having a diameter on the order of /s inch to /2 inch, with inch rollers being preferred, whereby the number of rollers may be greatly increased as compared to the number of rollers used in roller levelers, and the diameters of the rollers are greatly decreased as compared to the diameter of rollers of roller levelers, whereby a more severe stressing of the metal during each stressing thereof, is obtained and a larger number of stresses can be produced by a machine of a given size.

Still another object of this invention is to provide a novel machine for accomplishing the alternate flexing of continuous metal strip wherein there are many cycles of flexing accomplished on a strip by the machine and wherein the machine is provided with a large number of small diameter rollers, the rollers being arranged in a circular pattern and including an inner set of rollers and an outer set of rollers, and the outer set of rollers being mounted for movement outwardly with respect to the inner set of rollers to provide the necessary clearance for the initial feeding of an end of an elongated strip through the machine.

A further object of this invention is to provide a novel apparatus for accomplishing alternate flexing of continuous metal strip to produce alternate tension and compression strains therein, the machine being of a compact construction and including a central cylindrical support having a first set of rollers disposed thereabout, and a plurality of outer segmental supports carrying a second set of rollers for cooperation with the first set of rollers, the outer support being movable radially with respect to the central support for the purpose of spacing the outer set of rollers from the inner set of rollers to facilitate the initial feeding of a strip of metal between the two sets of rollers.

A still further object of this invention is to provide a novel apparatus for accomplishing the alternate flexing of continuous metal strip in order to produce alternate tensile and compressive plastic strains in the strip along lines transverse to the direction of strip motion, the device including two sets of rollers disposed in intermeshing relation and defining a sinusoidal path for a metal strip, with the path having a generally circular over-all outline, each set of rollers including small diameter rollers for engaging the sheet metal, and large diameter rollers backing up the small diameter rollers whereby the small diameter rollers may be journaled for rotation at the ends only thereof, the rollers backing up the small diameter rollers being arranged in rows along lines transverse to the direction of strip motion, and the rollers of adjacent rows being disposed in staggered overlapping relation whereby each of the small diameter rollers is supported by two sets of rollers.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings:

In the drawings:

FIGURE 1 is an end elevational view of the device or machine which is the subject of this invention, and shows the general layout thereof, portions of the roller supports being broken away and shown in section to clearly illustrate the details of the supporting of the rollers.

FIGURE 2 is an enlarged fragmentary elevational view of the roller support assembly of the machine, with portions of the supports being broken away and more clearly showing the arrangement of the rollers and the specific relationship of a metal strip with respect thereto.

FIGURE 3 is an enlarged fragmentary generally vertical sectional view taken along the line 3-3 of FIGURE 2, and shows the specific manner in which rollers of the outer set of rollers are supported.

FIGURE 4 is an enlarged fragmentary horizontal sectional view taken along the line 4-4 of FIGURE 2, and shows the specific relationship of the small diameter rolls with respect to each other and the specific backing up of the small diameter rolls, as well as the specific relationship of the metal strip with respect to the small diameter rolls.

Referring now to the drawings in detail, it will be seen that the over-all details of the machine, which is the subject of this invention, are best shown in FIGURE 1. The machine, which is generally referred to by the numeral 5, receives a strip S which is fed through the machine 5 in a continuous operation.

The strip S is relatively thick when it is initially rolled as compared to the final product. The strip S after being initially rolled, was annealed, after which it was passed through an electroplating bath in the customary manner so that tin coatings are applied to opposite faces thereof. The strip S, after having been coated, was then passed through a series of cold reduction rollers wherein the thickness of the strip S was reduced 30% to 60%. At the end of the rolling process, the strip S is in the form of a new type of hard, cold rolled tin plate which is now commercially available from a number of steel mills, e.g., from the US. Steel Corporation under the designation Ferrolite."

The 30% to 60% cold rolled plate or strip, as it comes from the cold reduction rollers of the steel mill, is relatively hard and brittle, and therefore is only suitable for limited field of usage by the can industry. However, it has a very great economic advantage, were the brittleness relieved by some operation. For every base box, i.e., 31,360 sq. in., which is coated with tin at a gauge, for example, of 0.012 inch, one obtains after cold rolling 50% a total of two base boxes of tin coated steel 0.006 inch thick. The low cost of rolling is such that doubling the area of product is accomplished at a much lower cost than would otherwise be possible. The steel industry has recognized the lower cost per unit of this hard rolled tin plate or strip, as compared to the conventional tin plate or strip, by pricing it at 55 per base box below that of conventional plate of the same gauge. Since the hard rolled plate is much stronger than conventional plate, one can use a thinner gauge of the hard rolled plate with a further increment of savings of materials cost amounting to 15 per box for every reduction in gauge of 0.00055 inch. A potential savings to the can industry by the use of the hard rolled plate adds up to many millions of dollars. However, the full utilization of such plate, and obtainment of related savings of metal costs, depends on the improvement in ductility of such hard and brittle plate which may be obtained by the use of the apparatus of this invention.

There is another equally or perhaps more important field of application of this invention. The hard rolled tin plate or strip referred to thus far has started as hot rolled steel strip which is cold rolled by to to perhaps. double the final gauge, then annealed, coated with tin and again cold rolled to a final gauge. It is possible instead to cold roll hot rolled strip directly to final gauge in a five or six tandem rolling mill. The cold reduction of 80% to results in extremly hard and strong steel strip which ordinarily is far too brittle to be used in the unannealed state. However, by partially restoring the ductility of such material with the practice of this invention, it could be employed for many purposes in the hard, unannealed state, either as is or with a subsequently applied tin coating or thin coating of other metal or material.

The high strength of the extremely hard rolled steel.

makes possible further reductions in gauge of metal for many fields of utilization, e.g., closures for cans. Not only are there substantial savings in amount of material, but the elimination of annealing and conventional temper rolling results in appreciable savings of process cost in the production of this hard rolled metal strip. While an appreciable savings in cost is expected, the exact cost savings is not yet known, because, until the present invention, there has been no way of utilizing such very hard and brittle plate and therefore the product has not been made nor priced commercially.

In accordance with this invention, either of these two types of hard rolled plate or strip or any other type of hard, brittle plate or strip may be further worked upon as part of the continuous forming thereof in the steel mill, or the plate or strip may be coiled subsequent to the cold reduction operation thereof and later worked upon in accordance with the invention either at the steel mill or at the can makers plant. For purposes of convenience, the working of the hard and strong but brittle cold rolled plate or strip S in accordance with the invention has been illustrated with the strip S being supplied in coil form.

Referring once again to FIGURE 1 of the drawings, it will be seen that the machine 5 includes a suitable base 6 which has a pair of standards 7 projecting upwardly from each end thereof. A suitable framework, generally referred to by the numeral 8, is carried by the standards 7. The framework 8 includes a pair of hubs 9 disposed at opposite ends of the machine 5. Each hub 9 has a plurality of arms 10 radiating therefrom. It is to be noted that the arms 10 are disposed in equally spaced relation about the respective hub 9. Two of the arms 10 at each end of the framework 8 are secured to the standards 7 at each end of the base 6. The connection between these certain arms 10 and the standards 7 is each referred to by the numeral 11.

The machine 5 includes a cylindrical support 12 which extends between the arms 10 at opposite ends of the framework 8 and is suitably secured thereto. The cylindrical support 12 carries an inner roller assembly, generally referred to by the numeral 13. The framework 8 includes an outer support 14 for each of the arms 10 at one end of the framework 8. Extending between every two aligned arms 10 at the opposite ends of the framework 8 is one of the outer supports 14. The supports 14 carry an outer roller assembly, generally referred to by the numeral 15. 1

At each end of the framework 8, an uppermost one of the supports 10 is provided with a standard 16a. A roller 17:: extends between the pair of standards 16a and has its ends suitably journaled relative thereto. The roller 17a is an idler roller and receives the strip S from an uncoiling unit (not shown). The framework 8 also includes a standard 18a which extends upwardly at each end thereof from the other of the uppermost ones of the arms 10. The two standards at the two ends of the framework 10 are in alignment and carry a pair of cooperating drive rollers 19a, 20a which are suitably driven. The strip S, after passing through the machine 5, passes around the drive roller 1% and is delivered to either a conventional roller leveler or a rewind stand (both of which are not shown). The roller 20a cooperates with the roller 19a to feed the strip S through the machine 5.

The inner roller assembly 13 is formed of a plurality of circumferentially spaced inner roller units, each generally referred to by the numeral 16, and all of the roller units 16 being identical. Each roller unit 16, as is best shown in FIGURES 2 and 4, includes a support, generally referred to by the numeral 17. In the form of the invention illustrated, each support 17 is formed of a plurality of plates or support elements 18 which extend circumferentially about the cylindrical support 12 and. which are in spaced parallel relation. Each support element 18 is secured to the cylindrical support 12 by suitable securing means, including welding 19. At this time, it is pointed out that in lieu of the support 17 being formed of a plurality of individual support elements 18, all of the support elements 18 could be integrally formed, and the support 17 secured as a unit to the cylindrical support 12.

Between each pair of support elements 18 a plurality of large diameter rollers 21) are mounted. Each large diameter roller 20 is carried by a shaft 21 which is supported by a pair of the support elements 18 and has the ends thereof terminating within the support elements 18. No bearing means have been shown. However, it is to be understood that each roller 20 could be rotatably journaled on its shaft 21, or each shaft 21 could be rotatably journaled in its respective support elements The large diameter rollers 20 of each roller unit 16 are disposed in rows extending longitudinally of the axis of the cylindrical support 12 and with transversely adjacent rollers being in overlapping relation so that the rollers 20 are disposed in rows and in staggered overlapping relation.

The outermost support elements of each of the supports 17 have suitably secured thereto 'arcuate support plates 22, with the support plates 22 being secured to the support elements 18 by means of bolts 23, as is shown in FIGURE 2. Each of the support plates 22 has an outer edge portion 24 of a generally scalloped or undulating appearance and defining a plurality of individual support portions 25 receiving reduced ends 26 of small diameter rollers 27. It is to be noted that each small diameter roller 27 is rotatably journaled only at the ends thereof by the reduced diameter portions 26. However, as is clearly shown in FIGURE 2, each small diameter roller 27 is supported by two rows of large diameter rollers 20. Thus, it will be apparent that each of the small diameter rollers 27 is rotatably journaled at it opposite ends and is supported intermediate its ends at transversely spaced intervals by large diameter rollers 20.

The outer roller assembly 15, like the inner roller assembly 13, is formed of a plurality of circumferentially spaced identicalroller units, each of which is referred to in general by the numeral 28. Each roller unit 28 is aligned with a respective one of the roller units 16. As is best shown in FIGURES 2, 3 and 4, each of the roller units 28 includes a support, generally referred to by the numeral 29. Each support 29 includes a base 30 having a plurality of spaced parallel support elements 31 projecting inwardly therefrom, the support elements 31 extending generally circumferentially around the cylindrical support 12. The support elements 31 receive the ends of short shafts 32, each short shaft 32 being supported by a pair of adjacent support elements 31. Each shaft 32 carries a large diameter roller 33 which is disposed between an adjacent pair of the support elements 31. The large diameter rollers 33 correspond to the large diameter rollers 20, and are mounted in rows extending axially of the cylindrical support 12 and in overlapping staggered relation, as is clearly shown in FIGURE 3. As mentioned with respect to the rollers 20 and the shafts 21, no bearing means has been illustrated with respect to the shafts 32 and the rollers 33. If desired, the rollers 33 may be suitably rotatably journaled on the shafts 32, or the shafts 32 may be suitably rotatably journaled in the support elements 31.

The endmost ones of the support elements 31 of each of the supports 29 carries an arcuate support 34 which is suitably secured to its respective support element 31 by means of bolts 35, for example, as is best shown in FIG- URE 2. Each of the supports 34 has a generally sinusoidal inner face 36 defining a plurality of shaft supporting portions 37. Each shaft supporting portion 37 receives a reduced end 38 of a small diameter roller 39, which corresponds to the small diameter rollers 27. Each small diameter roller 39 is rotatably journaled at its ends only, but is supported intermediate its ends by pairs of the large diameter rollers 33.

Each of the supports 14 carries an extensible hydraulic motor 40 which includes a shaft 41. The shaft 41, in turn, is secured to a plate 42 which is secured to the base 30 of an associated one of the supports 29. In this manner, each of the roller units 28 may be readily adjusted with respect to its respective roller unit 16. One of the primary advantages of the retractability of each of the roller units 28 is the fact that the roller units 28 may be sufliciently retracted to permit the feeding of the initial end of a strip, such as the metal strip S, through the machine 5. However, minor adjustments of the roller units 28 may be had for the purpose of compensating for variations in strip thickness.

Particular attention is directed to FIGURE 2, wherein it is shown that the small diameter rollers 27 of a roller unit. 16 are disposed in staggered relation with respect to the small diameter rollers 39 of a roller unit 28. Due to the particular intermeshing of the rollers 27 and 39 and the spacing of the rollers 27 and 39, it will be seen that the strip S, in passing through roller units 16 and 28, will pass along a sinusoidal path and will be reversely and alternatively flexed to produce alternate tension and compression strains in the strip along lines transverse to the direction of strip motion. Further, because of the small diameter of the rollers 27 and 39, the diameter of these rollers ranging from /s inch to inch and preferably inch, it will be seen that the strip S will be severely stressed as it is flexed around the rollers 27 and 39.

Particular reference is directed to FIGURE 2, wherein it will be apparent that the strip S must be flexed around two rollers, a roller 27 and a roller 39, to obtain a complete flexure of the strip S. Any number of flexures provided by the machine 5 must be within practical limits in order to permit the machine 5 to be of a sulficiently small size to be economically feasible. It is to be understood, however, that the number of the rollers 27 and 39 engaged with the strip S and the diameters of these rollers must be such as to produce more than a mere roller leveling of the strip S. As the hard, cold rolled strip S passes around the rollers 27 and 39, it must be stressed to the extent that at least the surface layer of the strip S in tension remote from the particular roller is stressed well beyond the yield strength of the metal of the hard rolled strip S. Further, in the working of the hard, cold rolled tin plate or strip having severely cold work steel substrate as the base thereof, the surface layer of the steel strip under compression is also stressed well beyond the yield strength of the metal of the strip S. Tests have indicated that the metal should be stressed beyond its yield strength to a depth of from to 40% of the thickness of the strip S inwardly from each stressed facing layer thereof. Of course, the deeper the penetration of work within the range specified, the fewer are the number of cycles of reverse stress required to obtain the desired increase in ductility, but flexing must obviously be stopped prior to the initiation of any fatigue damage.

For any given number of cycles of reverse reflexing, e.g., 10 or 100 or 1,000, there will be a stress below the ultimate tensile strength which will be sufiicient to cause fracture after the specified number of cycles of stressing. For the same number of cycles of stress, there will be a lower stress at which no fracture occurs but at which microcracks are formed which would ultimately cause fracture. The line of stress to cause microcracks versus the number of cycles to form these at each stress is called a damage curve. It is requisite, in the practice of this invention, that the number of cycles of stressing the surface layers beyond their yield strength by flexure should be less than the number of cycles to cause damage at the stress caused by that flexture. Ductility is increased by this invention when the combination of number of cycles of flexure and maximum flexural stress are so related that no fatigue damage occurs.

In test apparatus, it has been found that increase in ductility of the strip of hard, cold rolled tin plate in going from one to ten cycles of flexure was approximately equal to the increase of going from 10 to passes. Thus, while in general there was a continuing benefit, the benefit corresponded to the logarithmic increases in number of passes. From a commercial standpoint, it is believed that approximately 100 complete cycles of reverse flexing is the most economically feasible number considering results in the way of increase in ductility of the strip and the machinery required for obtaining an increased number of cycles of reverse flexure. This would require the engagement of the strip S width on the order of 100 of each of the rollers 27 and 39 as the strip S passes through the machine 5.

The machine 5 is particularly adaptable to the required reverse flexing of relatively thin strip, such as the strip S, in that adequate support is obtained for the very small diameter rollers so that a relatively severe flexing of the strip S can be obtained and at the same time, the machine 5 is extremely compact due to both the provision of the small diameter rollers and the arrangement of the rollers in a circular pattern in lieu of a longitudinal pattern. The particular circular pattern of the rollers 27 and 39 permits a machine of reasonable size to accomplish the desired flexing of a metal strip with the size of the machine being such that it may easily be placed in a metal strip line of any desired type.

From the foregoing, it will be seen that novel and advantageous provision has been made for carrying out the desired end. However, attention is directed to the fact that variations may be made in the example apparatus disclosed herein without departing from the spirit and scope of the invention, as defined in the appended claims.

I claim:

1. A device to accomplish alternate flexing of continuous metal strip in order to produce alternate tension and compression strains in the strip along lines transverse to the direction of strip motion to provide an increase in fabrication properties of severely Work hardened sheet metal comprising a first set of rollers and a second set of rollers, first roller support means mounting said first set of rollers with axes thereof disposed in an arcuate pattern, and second roller support means mounting said second set of rollers with the rollers of said second set of rollers in meshed relation with the rollers of said first set of rollers and with the axes of the rollers of said second set being disposed in a pattern concentric to the pattern of said first set of rollers.

2. A device to accomplish alternate flexing of continuous metal strip in order to produce alternate tension and compression strains in the strip along lines transverse to the direction of strip motion to provide an increase in fabrication properties of severely work hardened sheet metal comprising a first set of rollers and a second set of rollers, first roller support means mounting said first set of rollers with axes thereof disposed in an arcuate pattern, and second roller support means mounting said second set of rollers with the rollers of said second set of rollers in meshed relation with the rollers of said first set of rollers and with the axes of the rollers of said second set being disposed in a pattern concentric to the pattern of said first set of rollers, said second roller support means having adjustable mounting means whereby said second set of rollers may be moved away from said first set of rollers to provide clearance between the two sets of rollers for the initial feeding of the strip therebetween.

3. A device to accomplish alternate flexing of continuous metal strip in order to produce alternate tension and compression strains in the strip along lines transverse to the direction of strip motion to provide an increase in fabrication properties of severely work hardened sheet metal comprising a first set of rollers and a second set of rollers, first roller support means mounting said first set of rollers with axes thereof disposed in an arcuate pattern, and second roller support means mounting said second set of rolles with the rollers of said second set of rollers in mesh relation with the rollers of said first set of rollers and with the axes of the rollers of said second set being disposed in a pattern concentric to the pattern of said first set of rollers, said second roller support means including a plurality of circumferentially spaced supports each supporting a plurality of rollers of said second set of rollers, and adjustable mounting means mounting said circumferentially spaced supports for radial movement away from and towards said first set of rollers to provide clearance between said first and second sets of rollers for the initial feeding of the strip therebetween.

4. A device to .accomplish alternate flexing of continutinuous metal strip in order to produce alternate tension and compression strains in the strip along lines transverseto the direction of strip motion to provide an increase in fabrication properties of severely work hardened sheet metal comprising a first set of rollers and a second set of rollers, first roller support means mounting said first set of rollers with axes thereof disposed in an arcuate pattern, and second roller support means mounting said second set of rollers with the rollers of said second set of rollers in meshed relation with the rollers of said first set of rollers and with the axes of the rollers of said second set being disposed in a pattern concentric to the pattern of said first set of rollers, each of the rollers of said first and second sets of rollers having a diameter ranging from Ms inch to /2 inch.

5. A device to accomplish alternate flexing of continuous metal strip in order to produce alternate tension and compression strains in the strip along lines transverse to the direction of strip motion to provide an increase in fabrication properties of severely work hardened sheet metal comprising a first set of rollers and a second set of rollers, first roller support means mounting said first set of rollers with axes thereof disposed in an arcuate pattern, and second roller support means mounting said second set of rollers with the rollers of said second set of rollers in meshed relation with the rollers of said first set of rollers and with the axes of the rollers of said second set being disposed in a pattern concentric to the pattern of said first set of rollers, each of the rollers of said first and second sets of rollers having a diameter of approximately A inch.

6. A device to accomplish alternate flexing of continuous metal strip in order to produce alternate tension and compression strains in the strip along lines transverse to the direction of strip motion and to provide an increase in fabrication properties of severely work hardened sheet metal comprising a cylindrical support, a plurality of first support units carried by said cylindrical support in circumferentially spaced relation, a first set of small diameter rollers carried by said first support units in outwardly exposed relation, a plurality of second support units, each of said second support units being associated with one of said first support units and being disposed outwardly thereof, a second set of small diameter rollers carried by said second support units in inwardly disposed relation, said rollers of said second set of rollers being meshed with said rollers of said first set of rollers to define a tortuous reversing path for the strip being worked upon.

7. A device to accomplish alternate flexing of continuous metal strip in order to produce alternate tension and compression strains in the strip along lines transverse to the direction of strip motion to provide an increase in fabrication properties of severely work hardened sheet metal comprising a cylindrical support, a plurality of first support unit-s carried by said cylindrical support in circumferentially spaced relation, a first set of small diameter rollers carried by said first support units in outwardly exposed relation, a plurality of second support units, each of said second support units being associated with one of said first support units and being disposed outwardly thereof, a second set of small diameter rollers carried by said second support units in inwardly disposed relation, said rollers of said second set of rollers being meshed with said rollers of said first set of rollers to define a tortuous reversing path for the strip being worked upon, said second support units having adjustable mounting means whereby said second set of rollers may be moved away from said first set of rollers to provide clearance between the two sets of rollers for the initial feeding of the strip therebetween.

8. A device to accomplish alternate flexing of continuous metal strip in order to produce alternate tension and compression strains in the strip along lines transverse to the direction of strip motion to provide an increase in fabrication properties of severely work hardened sheet metal comprising a first set of rollers and a second set of rollers, first roller support means mounting said first set of rollers with axes thereof disposed in an arcuate patter-n, and second roller support means mounting said second set of rollers with the rollers of said second set of rollers in meshed relation with the rollers of said first set of rollers and with the axes of the rollers of said second set being disposed in a pattern concentric to the pattern of said first set of rollers, said first roller support means including first supports carrying said first set of rollers, first large diameter rollers carried by said first supports and backing up said first set of rollers to prevent deflection thereof, second supports carrying said second set of rollers, and second large diameter rollers carried by said second supports and backing up said second set of rollers to prevent deflection thereof.

9. The device of claim 8 wherein each of said first and second supports include a plurality of spaced parallel support members, short shafts carried by adjacent ones of said support members, and a respective one of said first and second large diameter rollers carried by each short shaft.

10. The device of claim 8 wherein the rollers of each of said first and second large diameter rollers are arranged in rows axially of the rollers of said first and second sets of rollers and in staggered overlapping relation.

11. The device of claim 8 wherein each of said first and second supports include a plurality of spaced parallel support members, short shafts carried by adjacent ones of said support members, and a respective one of said first and second large diameter rollers carried by each short shaft, and the rollers of each of said first and second large diameter rollers are arranged in rows axially of the rollers of said first and second sets of rollers and in staggered overlapping relation.

12. A device to accomplish alternate flexing of continuous metal strip in order to produce alternate tension and compression strains in the strip along lines transverse to the direction of strip motion and to provide an increase in fabrication properties of severely work hardened sheet metal comprising a cylindrical support, a plurality of first support units carried by said cylindrical support in circumferentially spaced relation, a first set of small diameter rollers carried by said first support units in outwardly exposed relation, a plurality of second support units, each of said second support units being associated with one of said first support units and being disposed outwardly thereof, a second set of small diameter rollers carried by said second support units in inwardly disposed relation, said roller-s of said second set of rollers being meshed with said rollers of said first set of rollers to define a tortuous reversing path for the strip being worked upon, each of said support units also carrying a plurality of large diameter rollers engaging and backing up respective ones of said small diameter rollers.

13. The device of claim 12 wherein said large diameter rollers of each support unit are arranged in rows axially 1 1 of said small diameter rollers and in staggered overlapping relation.

14. A device to accomplish alternate flexing of continuous metal strip in order to produce alternate tension and compression strains in the strip along lines transverse to the direction of strip motion to provide an increase in fabrication properties of severely work hardened sheet metal comprising a cylindrical support, a plurality of first support units carried by said cylindrical support in circumferentially spaced relation, a first set of small diameter rollers carried by said first support units in outwardly exposed relation, a plurality of second support units, each of said second support units being associated with one of said first support units and being disposed outwardly thereof, a second set of small diameter rollers carried by said second support units in inwardly disposed relation, said rollers of said second set of rollers being meshed with said rollers of said first set of rollers to define a tortuous reversing path for the strip being worked upon, each of said support units also carrying a plurality of large diameter rollers engaging and backing up respective ones of said small diameter rollers, each of said support units including spaced parallel support members extending generally normal to the axes of said small diameter rollers, short shafts carried by adjacent ones of said support members, and one of said large diameter rollers carried by each of said shafts.

15. The device of claim 14 wherein said large diameter rollers of each support unit are arranged in rows axially of said small diameter rollers and in staggered overlapping relation.

16. The device of claim 14 wherein the diameter of each of said small diameter rollers is between 43 inch and /2 inch.

17. The device of claim 14 wherein the diameter of each of said small diameter rollers is approximately inch.

References Cited by the Examiner UNITED STATES PATENTS Re. 20,404 6/37 Ungerer 153l06 1,715,219 5/29 Biggert. 1,930,562 10/33 Krueger. 2,004,596 6/35 Biggert 153106 XR 2,578,820 12/51 Mayer 15393 3,078,908 2/63 Maust 153-86 CHARLES W. LANHAM, Primary Examiner.

WILLIAM J. STEPHENSON, Examiner. 

1. A DEVICE TO ACCOMPLISH ALTERNATE FLEXING OF CONTINUOUS METAL STRIP IN ORDER TO PRODUCE ALTERNATE TENSION AND COMPRESSION STRAINS IN THE STRIP ALONG LINES TRANSVERSE TO THE DIRECTION OF STRIP MOTION TO PROVIDE AN INCREASE IN FABRICATION PROPERTIES OF SEVERLEY WORK HARDENED SHEET METAL COMPRISING A FIRST SET OF ROLLERS AND A SECOND SET OF ROLLERS, FIRST ROLLER SUPPORT MEANS MOUNTING SAID FIRST SET OF ROLLERS WITH AXES THEREOF DISPOSED IN AN ARCUATE PATTERN, AND SECOND ROLLER SUPPORT MEANS MOUNTING SAID SECOND SET OF ROLLERS WITH THE ROLLERS OF SAID SECOND SET OF ROLLERS IN MESHED RELATION WITH THE ROLLERS OF SAID FIRST SET OF ROLLERS AND WITH THE AXES OF THE ROLLERS OF SAID SECOND SET BEING DISPOSED IN A PATTERN CONCENTRIC TO THE PATTERN OF SAID ROLLERS. 